Communication systems typically operate in accordance with one or more communication standards. Wireless communication systems may operate in accordance with one or more standards including, but not limited to, Institute of Electrical and Electronics Engineers (IEEE) 802.11, Wi-Fi Direct, Bluetooth, advanced mobile phone services (AMPS), digital AMPS, global system for mobile communications (GSM), code division multiple access (CDMA), local multi-point distribution systems (LMDS), multi-channel-multi-point distribution systems (MMDS), time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, 3GPP Long Term Evolution (LTE) systems, and orthogonal frequency division multiple access (OFDMA) systems.
Some conventional advanced devices include multiple radios for transmitting/receiving using different Radio Access Technologies (RATs). Examples of RATs include, e.g., Universal Mobile Telecommunications System (UMTS), Global System for Mobile Communications (GSM), cdma2000, WiMAX, WLAN (e.g., WiFi), Bluetooth, LTE, and the like.
An example mobile device includes an LTE User Equipment (UE), such as a fourth generation (4G) or fifth generation (5G) mobile phone. Such 4G or 5G phone may include various radios to provide a variety of functions for the user. For purposes of this example, the 4G or 5G phone includes an LTE radio for voice and data, an IEEE 802.11 (WiFi) radio, a Global Positioning System (GPS) radio, and a Bluetooth radio, where two or more of the above may operate simultaneously. While the different radios provide useful functionalities for the phone, their inclusion in a single device gives rise to coexistence issues. Specifically, operation of one radio may in some cases interfere with operation of another radio through radiative, conductive, resource collision, and/or other interference mechanisms. Coexistence issues include such interference.
This is especially true for the LTE uplink channel, which is adjacent to the Industrial Scientific and Medical (ISM) band and may cause interference therewith. It should be noted that Bluetooth and some Wireless LAN (WLAN) channels fall within the ISM band, and FIG. 1, for example, illustrates a Bluetooth and an adjacent LTE band. Wi-Fi and Bluetooth both occupy a section of the 2.4 GHz ISM band that is 83 MHz-wide. Bluetooth uses Frequency Hopping Spread Spectrum (FHSS) and is allowed to hop between 79 different 1 MHz-wide channels in this band. In some instances, a Bluetooth error rate can become unacceptable when LTE is active in some channels of Band 40 or even Band 7 for some Bluetooth channel conditions. Consequently, simultaneous operation with Bluetooth can result in disruption in voice services terminating in a Bluetooth headset. Such disruption may be unacceptable to the consumer. In some instances, Bluetooth or WLAN error rate can become unacceptable when WLAN is active and the one of the plurality of hoping frequencies of the BT device is in proximity to the WLAN channel.